Skeletal System Bone formation: bones start as cartilage and slowly it is replaced by bone

Structures: bone tendons ligaments cartilage

Functions: 1. Gives Shape and support to the body 2. Protect your internal organs 3. Major muscles attach to bones to help you move 4. Blood cells are formed in the bone. (The tissue called marrow) 5. Store calcium and phosphorous compounds (calcium and phosphorous compounds make bones hard)

Bone Major organs of the skeletal system Adult skeleton composed of 206 bones Store minerals In certain bones, bone marrow produces blood cells Picture: Ulna and radius bones in the forearm

Structure of Bones

Periosteum : thin tough layer that covers all the bones, except the part of the bone that is in the joint. Blood vessels in the pariosteum carry the nutrients to the bone and cell that repair and cause growth are here.

Compact bone: right under the periostreum this layer is the hard strong part. This layer gives bones strength contains deposits of calcium phosphate.

Spongy Bone: is locate at the end of the long bones like those in your arms and legs. This part of the bone has lots of open spaces which keeps the bones light weight.

Cavities: are the center of the long bones and contain the marrow Marrow: some marrow is red some yellow. Red marrow produced red blood (2 to 3 million per second) cells, yellow marrow is made up of fat.

Connective Tissue Ligament Tendon Connects bone to bone Connects skeletal muscle to bone Skeletal muscle Picture (Left): Ligament in the ankle Picture (Right): Achilles Tendon Tendon Bone

Cartilage: soft and flexible tissue that provides padding in between bones.

Ligament Connect Bone to Bone

Tendon Connect Muscle to Bone

Joints Of the Human Body Any place where two or more bones come together . Some joints move and others do not.

Types of Joints Immovable Moveable Skull Pelvis Pivot Ball & socket Hinge Gliding

Immovable Joint No movement takes place at these type of joints

Ball and Socket Joint Bone with a rounded end that fits into a cuplike cavity on another bone

Gliding Joint One part of a bone slides over another bone

Pivot Joint One bone rotates in a ring of another bone that does not move.

Hinge Joint Back-and-forth movement like hinges on a door